• Genomics & Informatics
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• v.20 no.2
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• pp.23.1-23.9
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• 2022

A survival prediction model has recently been developed to evaluate the prognosis of resected nonmetastatic pancreatic ductal adenocarcinoma based on a Cox model using two nationwide databases: Surveillance, Epidemiology and End Results (SEER) and Korea Tumor Registry System-Biliary Pancreas (KOTUS-BP). In this study, we applied two machine learning methods-random survival forests (RSF) and support vector machines (SVM)-for survival analysis and compared their prediction performance using the SEER and KOTUS-BP datasets. Three schemes were used for model development and evaluation. First, we utilized data from SEER for model development and used data from KOTUS-BP for external evaluation. Second, these two datasets were swapped by taking data from KOTUS-BP for model development and data from SEER for external evaluation. Finally, we mixed these two datasets half and half and utilized the mixed datasets for model development and validation. We used 9,624 patients from SEER and 3,281 patients from KOTUS-BP to construct a prediction model with seven covariates: age, sex, histologic differentiation, adjuvant treatment, resection margin status, and the American Joint Committee on Cancer 8th edition T-stage and N-stage. Comparing the three schemes, the performance of the Cox model, RSF, and SVM was better when using the mixed datasets than when using the unmixed datasets. When using the mixed datasets, the C-index, 1-year, 2-year, and 3-year time-dependent areas under the curve for the Cox model were 0.644, 0.698, 0.680, and 0.687, respectively. The Cox model performed slightly better than RSF and SVM.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1407-1412
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• 2012

Background & Objectives: Gastric cancer is a leading cause of cancer-related deaths in both sexes in Iran. This study was designed to assess upper GI endoscopic findings among people > 50 years targeted in a mass screening program in a hot-point region. Methods: Based on the pilot results in Guilan Cancer Registry study (GCRS), one of the high point regions for GC-Lashtenesha- was selected. The target population was called mainly using two methods: in rural regions, by house-house direct referral and in urban areas using public media. Upper GI endoscopy was performed by trained endoscopists. All participants underwent biopsies for rapid urea test (RUT) from the antrum and also further biopsies from five defined points of stomach for detection of precancerous lesions. In cases of visible gross lesions, more diagnostic biopsies were taken and submitted for histopathologic evaluation. Results: Of 1,394 initial participants, finally 1,382 persons (702 women, 680 men) with a mean age of $61.7{\pm}9.0$ years (range: 50-87 years) underwent upper GI endoscopy. H. pylori infection based on the RUT was positive in 66.6%. Gastric adenocarcinoma and squamous cell carcinoma of esophagus were detected in seven (0.5%) and one (0.07%) persons, respectively. A remarkable proportion of studied participants were found to have esophageal hiatal hernia (38.4%). Asymptomatic gastric masses found in 1.1% (15) of cases which were mostly located in antrum (33.3%), cardia (20.0%) and prepyloric area (20.0%). Gastric and duodenal ulcers were found in 5.9% (82) and 6.9% (96) of the screened population. Conclusion: Upper endoscopy screening is an effective technique for early detection of GC especially in high risk populations. Further studies are required to evaluate cost effectiveness, cost benefit and mortality and morbidity of this method among high and moderate risk population before recommending this method for the GC surveillance program at the national level.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6357-6362
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• 2014

Background: Globally, the overall incidence of cancer is increasing as a result of ageing populations and changing lifestyles. Cancer is one of the leading causes of death, especially in the developed nations. Cancers affecting the young population are generally considered uncommon. This study assessed the demography and trends of cancers of the young in Brunei Darussalam, a small and developing Southeast Asia nation. Materials and Methods: All patients diagnosed with cancers between 2000 and 2012 were identified from the cancer registry maintained by the State Histopathology Laboratory. Cancers of the young was defined as any cancers diagnosed under the age of 40 years. Demographic data and the type of cancers were collected and analysed using SPSS Statistics 17.0. Results: Among the 6,460 patients diagnosed with cancer over the study period, 18.7% (n=1,205) were categorized as young with an overall decline in the proportion from 26.6% in 2000 to 18.8% in 2012 (p<0.001 for trend). Among all cancers of the young, the most common systems affected were gynecological (24.1%), hematological/lymphatic (15.8%), subcutaneous/dermatological/ musculoskeletal (10.5%), breast (10.5%) and gastrointestinal (9.9%). Overall, among the different systems, neurological (54.9%) had the highest proportion of cancers of the young followed by gynecological/reproductive (30.6%), hematological/lymphatic (39.9%), endocrine (38.7%), subcutaneous/dermatological/ musculoskeletal (22.3%) and the head and neck region (20.1%). There was a female predominance (66.9%) and the incidence was significantly higher among the Malays (20.1%) and expatriates (25.1%) groups compared to the Chinese (10.7%) and indigenous (16.8%) groups (p<0.001 for trend). Conclusions: Cancers of the young (<40 years) accounted for almost a fifth of all cancers in Brunei Darussalam with certain organ systems more strongly affected. There was a female preponderance in all racial groups. Over the years, there has been a decline in the overall proportion of cancers of the young. Selective screening programs should nevertheless be considered.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.10
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• pp.4591-4597
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• 2016

Purpose: Decisions as to whether to provide adjuvant treatment in older breast cancer patients remains challenging. Side effects of chemotherapy have to be weighed against life expectancy, comorbidities, functional status, and frailty. To aid decision-making, we retrospectively analyzed 110 women with breast cancer treated with a curative intention from 2006 to 2012. Survival data with clinical and pathological parameters were evaluated to address the role of adjuvant chemotherapy in this study population. Method: A total of 110 elderly (>70 years) patients that received mastectomy at two hospitals in Taiwan were observed retrospectively for a medium of 51 months. After mastectomy, patients received conservative treatment or adjuvant chemotherapy, or hormone therapy following clinical guidelines or physician's preference. Data were collected from the cancer registry system. Results: Median age at diagnosis was 75.7 years. Thirty-five percent of patients received adjuvant chemotherapy, these having a significantly younger age ($mean=74.0{\pm}5.3$ vs $77.5{\pm}5.3$, p<0.001) and higher tumor staging (p=0.003) compared with their non-chemotherapy counterparts.Five-year overall survival was non-significantly higher in patients who received adjuvant chemotherapy (with chemotherapy 64.2% vs without chemotherapy 62.6%, p=0.635), while five-year recurrence free survival was non-significantly lower (with chemotherapy 64.1% vs without chemotherapy 90.5%, p=0.80). Conclusions: In this analysis, adjuvant chemotherapy tended to be given to patients with a younger age and higher tumor staging at our institute. It was not associated with any statistically significant improvement in survival and recurrence rate. Until age specific recommendations are available, physicians must use their clinical judgment and assess the tumor biology with the patient's comorbidities to make the best choice. Clinical trials focusing on this critical issue are warranted.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10263-10266
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• 2015

Background: The risk of febrile neutropaenia (FN) and treatment related death (TRD) with first line palliative chemotherapy for de novo metastatic breast cancer (MBC) remains unknown outside of a clinical trial setting despite its widespread usage. This study aimed to determine rates in a large cohort of patients treated in the University of Malaya Medical Centre (UMMC). Materials and Methods: Patients who were treated with first line palliative chemotherapy for de novo MBC from 2002-2011 in UMMC were identified from the UMMC Breast Cancer Registry. Information collected included patient demographics, histopathological features, treatment received, including the different chemotherapy regimens, and presence of FN and TRD. FN was defined as an oral temperature > $38.5^{\circ}C$ or two consecutive readings of > $38.0^{\circ}C$ for 2 hours and an absolute neutrophil count < $0.5{\times}10^9/L$, or expected to fall below $0.5{\times}10^9/L$ (de Naurois et al, 2010). TRD was defined as death occurring during or within 30 days of the last chemotherapy treatment, as a consequence of the chemotherapy treatment. Statistical analysis was performed using the SPSS version 18.0 software. Survival probabilities were estimated using the Kaplan-Meier method and differences in survival compared using log-rank test. Results: Between $1^{st}$ January 2002 and $31^{st}$ December 2011, 424 patients with MBC were treated in UMMC. A total of 186 out of 221 patients with de novo MBC who received first line palliative chemotherapy were analyzed. The mean age of patients in this study was 49.5 years (range 24 to 74 years). Biologically, ER status was negative in 54.4% of patients and Her-2 status was positive in 31.1%. A 5-flourouracil, epirubicin and cyclophosphamide (FEC) chemotherapy regimen was chosen for 86.6% of the cases. Most patients had multiple metastatic sites (58.6%). The main result of this study showed a FN rate of 5.9% and TRD rate of 3.2%. The median survival (MS) for the entire cohort was 19 months. For those with multiple metastatic sites, liver only, lung only, bone only and brain only metastatic sites, the MS was 18, 24, 19, 24 and 8 months respectively (p-value= 0.319). Conclusions: In conclusion, we surmise that FEC is a safe regimen with acceptable FN and TRD rates for de novo MBC.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.347-354
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• 2014

Korea Central Cancer Registry reported in 2011 that the prevalence rate of thyroid cancer was about 19.6% (the highest) in both men and women. The ratio of thyroid cancer, among cancers that women suffer from, was about 31.1%, the highest among female cancers and about five times more than men. Regarding the incidence of thyroid cancer by age group, the crude rate was highest in women and men aged 15~34. From these figures it can be inferred that there is a greater relationship between thyroid cancer and hormones compared with other cancers. Therefore, young women aged 20~25, even if they are in full health, should undergo a medical examination. This study is aimed at examining changes in thyroid gland detected through self evaluation tests and the analysis of ultrasound screening images in persons aged 20~25. According to the study, 213 persons (about 46.6%) out of 457 people who took part in the study had abnormal echo patterns. With regard to women's abnormal patterns, about 73.4% of them were found to have calcified cystic, 11.8% diffuse-type low-echo and 7.3% cystic echo. With regard to male participants, about 61.1% were found to have calcified cystic, followed by 19.4% with the size of the isthmus increased and 13.9% with diffuse-type low-echo. According to the outcomes of an analysis regarding self-testing for hyperthyroidism, the average points of participants who were found to have abnormal echo patterns in ultrasound tests were 6.85 and the figure was 5.88 in persons with normal patterns. The figure was about 15% higher in abnormal respondents.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4587-4592
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• 2012

Purpose: This study used receiver operating characteristic curve to analyze Surveillance, Epidemiology and End Results (SEER) neuroblastoma (NB) and other peripheral nerve cell tumors (PNCT) outcome data. This study found under usage of radiotherapy in these patients. Materials and methods: This study analyzed socio-economic, staging and treatment factors available in the SEER database for NB and other PNCT. For the risk modeling, each factor was fitted by a generalized linear model to predict the outcome (soft tissue specific death, yes/no). The area under the receiver operating characteristic curve (ROC) was computed. Similar strata were combined to construct the most parsimonious models. A random sampling algorithm was used to estimate the modeling errors. Risk of neuroendocrine (other endocrine including thymus as coded in SEER) death was computed for the predictors. Results: There were 5261 patients diagnosed from 1973 to 2009 were included in this study. The mean follow up time (S.D.) was 83.8 (97.6) months. The mean (SD) age was 18 (25) years. About 30.45% of patients were un-staged. The SEER staging has high ROC (SD) area of 0.58 (0.01) among the factors tested. We simplified the 4-layered risk levels (local, regional, distant, un-staged/others) to a simpler 3-tiered model with comparable ROC area of 0.59 (0.01). Less than 50% of PNCT patients received radiotherapy (RT) including the ones with localized disease. This avoidance of RT use occurred in adults and children. Conclusion: The high under-staging rate may have precented patients from selecting definitive radiotherapy (RT) after surgery. Using RT for, especially, adult PNCT patients is a potential way to improve outcome.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.867-870
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• 2014

Purpose: This study used receiver operating characteristic curve to analyze Surveillance, Epidemiology and End Results (SEER) ependymoma data to identify predictive models and potential disparity in outcome. Materials and Methods: This study analyzed socio-economic, staging and treatment factors available in the SEER database for ependymoma. For the risk modeling, each factor was fitted by a Generalized Linear Model to predict the outcome ('brain and other nervous systems' specific death in yes/no). The area under the receiver operating characteristic curve (ROC) was computed. Similar strata were combined to construct the most parsimonious models. A random sampling algorithm was used to estimate the modeling errors. Risk of ependymoma death was computed for the predictors for comparison. Results: A total of 3,500 patients diagnosed from 1973 to 2009 were included in this study. The mean follow up time (S.D.) was 79.8 (82.3) months. Some 46% of the patients were female. The mean (S.D.) age was 34.4 (22.8) years. Age was the most predictive factor of outcome. Unknown grade demonstrated a 15% risk of cause specific death compared to 9% for grades I and II, and 36% for grades III and IV. A 5-tiered grade model (with a ROC area 0.48) was optimized to a 3-tiered model (with ROC area of 0.53). This ROC area tied for the second with that for surgery. African-American patients had 21.5% risk of death compared with 16.6% for the others. Some 72.7% of patient who did not get RT had cerebellar or spinal ependymoma. Patients undergoing surgery had 16.3% risk of death, as compared to 23.7% among those who did not have surgery. Conclusion: Grading ependymoma may dramatically improve modeling of data. RT is under used for cerebellum and spinal cord ependymoma and it may be a potential way to improve outcome.

• Journal of Preventive Medicine and Public Health
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• v.40 no.3
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• pp.249-258
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• 2007

Objectives : The aims of this study were to estimate the antihypertensive medication adherence in people with a disability and a history of taking antihypertensive medication, and to identify the factors affecting medication adherence. Methods : The National Health Insurance claims data were linked with the National Disability Registry. People with a disability, who received a prescription of antihypertensives, were identified from a total of 85,098 cases. Cumulative medication adherence (CMA) was used as an indicator of medication adherence. A CMA > 80% was defined as appropriate medication adherence. Multiple logistic regression analysis was used to identify the factors affecting medication adherence. Results : The average CMA in a total of 85,098 patients was 79.5%. The appropriate adherence $(CMA{\geq}80%)$ rate was 54.5% and 20.5% of patients had a CMA < 50%. Multiple logistic regression analysis revealed that the probability of appropriate adherence decreased with decreasing number of prescription days per visit, increasing number of providers, the patients' residential area moving from urban to rural areas, and when patients have an internal organ disability, auditory impairment, mobility impairment. Conclusions : The adherence to antihypertensive medication in people with a disability is influenced by various socio-economic, clinical and regional factors. In particular, the disabled who have locomotive and communication disabilities and internal organ impairments have a higher probability of under-adherence to antihypertensive medication adherence in Korea.

• Archives of Plastic Surgery
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• v.45 no.3
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• pp.239-245
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• 2018

Background Breast reconstruction has become more common as mastectomy has become more frequent. In Korea, the National Health Insurance Service (NHIS) began covering breast reconstruction in April 2015. This study aimed to investigate trends in mastectomy and breast reconstruction over the past 10 years and to evaluate the impact of NHIS coverage on breast reconstruction. Methods Nationwide data regarding mastectomy and breast reconstruction were collected from the Korean Breast Cancer Society registry database. Multiple variables were analyzed in the records of patients who underwent breast reconstruction from January 2005 to March 2017 at a single institution. Results At Seoul National University Hospital, the total number of reconstruction cases increased 13-fold from 2005 to 2016. The proportion of immediate breast reconstruction (IBR) cases out of all cases of total mastectomy increased from 4% in 2005 to 52.0% in 2016. The proportion of delayed breast reconstruction (DBR) cases out of all cases of breast reconstruction and the overall number of DBR cases increased from 8.8% (20 cases) in 2012 to 18.3% (76 cases) in 2016. After NHIS coverage was initiated, the proportions of IBR and DBR showed statistically significant increases (P<0.05). Among the IBR cases, the percentage of prosthesis-based reconstructions increased significantly (P<0.05), but this trend was not found with DBR. Total mastectomy became significantly more common after the expansion of NHIS coverage (P<0.05). Conclusions Over the last decade, there has been an increase in mastectomy and breast reconstruction, and the pace of increase accelerated after the expansion of NHIS coverage. It is expected that breast reconstruction will be a routine option for patients with breast cancer under the NHIS.